Laboratory trace and ultra-trace analysis often requires an ultra-pure acid, so an acid of ordinary purity needs to be slowly evaporated in a sub-boiling state and to be condensed and collected as a purer acid.
A purifier generally has a heating function, a temperature control function, a liquid level monitoring function and a condensation function, to perform heating, temperature control, liquid level monitoring and condensation as well as collection on an acid liquid.
In purifier design currently available in a market, there are usually shortcomings in aspects as follows:
1. Temperature Control:
(1) In a conventional solution, in order to avoid a temperature sensor from being easily corroded by high temperature strong acid, the temperature sensor is installed outside a container, to avoid contact with the strong acid; however, in such an installation mode, it is temperature of an outer wall of the container that is measured, which cannot reflect true temperature of the acid liquid, usually there is a difference of 5° C. to 20° C. between temperature of a solution and the temperature of the outer wall of the container, so a temperature measurement error is great.
(2) In the conventional solution, a temperature controller is a multi-position type, rather than a continuously adjustable type, which may only set a temperature value roughly and cannot set accurately.
2. Liquid Level Control:
(1) With respect to a liquid level of a raw acid liquid, in the conventional solution, the liquid level of a liquid level pipe is determined in a mode of visual inspection; once personnel forget to perform visual inspection in time, there will be a huge risk of dry burning or even breaking out of fire.
(2) With respect to a liquid level of a high-purity acid liquid, there is no automatic detection and control measure in the existing solution. Once the liquid level is overfilled, the acid liquid will spill out of a bottle and corrode surrounding objects.
3. Condensation Control and Heating Control:
(1) An air cooling mode or a tap water cooling mode is used in the existing solution. Both modes show no temperature indicating a cooling effect.
(2) Both modes are susceptible to influence of air temperature and tap water temperature conditions; once the air temperature or the water temperature rises, the cooling effect will be affected.
(3) A tap water cooling mode also has a risk of incapability of cooling down due to a lack of water supply.
(4) An infrared lamp or a resistance wire is used as a heat source in the existing solution, which is open flame and easily ignites an inflammable gas around;
(5) Once the temperature controller fails, the infrared lamp or the resistance wire will continue to heat, causing a great risk of burning down an instrument or even a laboratory fire.